Method For Installing A Solidifying Material Pier Anchorage System

ABSTRACT

This invention relates to a method for installing anchorage apparatus used in stabilizing different types of soils and/or creating anchorage and more particularly, to a method for injecting various types of solidifying material into a subsurface through a anchorage apparatus during the drilling operation. The anchorage apparatus may be used in conjunction with grout and similar materials for forming an anchor or load carry pier. A solidifying material swivel, a drive connector and a anchorage apparatus, in combination are attached to a power drive unit such that after insertion, the anchorage apparatus remains within the soil subsurface, encased in solidifying material.

CROSS REFERENCE TO RELATED APPLICATIONS

This application in a continuation-in-part and claims benefit of U.S. application Ser. No. 11/423,323 filed Jun. 9, 2006, incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to a method of installing a pier anchorage system used in stabilizing different types of soils and/or creating anchorage, and more particularly, but not by way of limitation, to a method of installing a pier that permits injecting various types of solidifying material into a subsurface during its placement.

BACKGROUND OF THE INVENTION

Soil stabilization techniques such as helical plate bearing anchors, mini-piles and micro-piles are known. For example, helical plate bearing anchors are mounted on steel bar shafts and pipe shafts with plate helices that are drilled into soil and used as tension, compression and lateral force resisting members. These types of anchors may be mounted to hollow shafts to provide a channel for injecting solidifying material into the subsurface after drilling is completed. For example, hollow drill rods and drill shafts are used with grout in forming tiebacks, mini-piles, rock anchors, soil nails and other micro-pile uses.

Further, various types of auger tools are used for excavating holes. This type of tool may have a disposable drill head. Flight augers have continuous helices along the length of the shaft. Because of the expense of this type of auger, the auger is generally removed from a drill hole and not left in place, the drill hole subsequently filled with solidifying material to form a mini-pile.

In U.S. Pat. No. 5,575,593 to Raaf, a method and apparatus for installing a helical pier with pressurized grouting is disclosed. An anchor having helices is rotated into the ground. The helical anchor is hollow and includes multiple perforated holes along its length and about its perimeter. After the anchor is drilled into the ground, pressurized grout is injected therein and forced out the perforated holes.

In U.S. Pat. No. 4,009,582 to LeCorgne, a method is described for forming a caseless concrete pile using a hollow pipe, a connector and a tubular driving mandrel. In U.S. Pat. No. 3,512,366 to Turzillo, a hollow auger for drilling holes is disclosed. The auger described in the Turzillo patent is withdrawn from the hole leaving a steel rod with drill bit in place with concrete thereafter poured for forming a concrete pier.

In U.S. Pat. Nos. 4,492,493 and 4,756,129 to Webb and 3,115,226 to Thompson, Jr. different types of ground anchors and apparatus are described. Also, U.S. Pat. Nos. 4,998,849 to Summers, 3,961,671 to Adams et al. and 4,678,373 to Langenbach, Jr. disclose different types of driving apparatus and methods of shoring structures.

Other varieties of ground anchor devices used for soil stabilization have been described. In particular, U.S. Pat. No. 6,722,821 to Perko et al. and U.S. Pat. Nos. 5,904,447, 5,919,005 and 5,934,836 to Rupiper et al. disclose recent anchor devices using helical piers for stabilizing soil and for securing building foundations and other structures.

The above described and other known soil stabilization and anchoring techniques include either pumping a solidifying material under pressure through a hollow anchorage apparatus and out holes contained therein once the anchorage apparatus has been advanced into the ground subsurface, or alternatively, withdrawing the anchorage apparatus and thereafter pumping a solidifying material under pressure into the space created by the anchorage apparatus. Unfortunately, such post-drilling operation techniques leave voids both within the solidifying material and between the solidifying material and soil with resulting loss of soil stabilization and resistance to displacement.

Accordingly, there is still a continuing need for improved helical pier designs that result in voidless solidifying material placement. In presenting a novel helical pier to deliver the solidifying material during the drilling process, the present invention fulfills this need and further provides related advantages.

BRIEF SUMMARY OF THE INVENTION

The method of soil stabilization and anchoring described herein teaches the unique combination of structure and functions to allow a solidifying material to be pumped under pressure during the drilling process, thereby preventing voids both within the solidifying material and between the solidifying material and soil, resulting in increased soil stabilization and resistance to displacement.

In a preferred embodiment, a pilot hole is drilled to a predetermined depth and angulation, followed by insertion of a anchorage apparatus which remains within the soil subsurface, encased in solidifying material.

The anchorage apparatus includes at least one hollow pipe section. In the preferred embodiment, at least one helice is attached to the pipe section. The helice is used for driving the pipe section into the pilot hole and for additional resistance to displacement forces once the drilling is completed. At least one perforation in the pipe section is used for introducing a solidifying material under pressure into the soil subsurface during the pipe section insertion process. The solidifying material is pumped under pressure into the hollow pipe section while the anchorage apparatus is being operatively engaged. The anchorage apparatus remains in the soil encased in solidifying material to increase soil stabilization and/or create an anchor point or load carry pier.

In a preferred embodiment, an upper end of the anchorage apparatus attaches to a drive connector allowing for operative attachment of a solidifying material swivel to the anchorage apparatus. The solidifying material swivel comprises a drive shaft which extends through a stationary casing at both ends and is adapted at an upper end to accept a power driving device, for example, various types of torque, hydraulic and percussion drives for drilling into different types of soils. A lower end of the anchorage apparatus includes components used for advancing downwardly into the soil, for example, a cutter head, a helix, a drill point and the like.

One advantage of the present invention is that it provides a system which is adaptable for faster, easier injection of solidifying material into a soil subsurface during the composite pier placement process, thereby achieving voidless soil stabilization, load carrying and anchorage.

Another advantage of the invention is that the composite pier can be driven into the ground surface at predetermined precise locations using easily interchangeable types of torque, hydraulic and percussion drilling machines.

Yet another advantage of the invention is that it provides a rugged yet relatively inexpensive drilling system that can be used interchangeably to form either a voidless anchor or load carry pier.

Still another advantage of the invention is that the system allows for rapid, stable and uniform construction of voidless anchors or load carry piers on all types of terrain and soil conditions.

Yet another advantage of the invention is the ease with which soil stabilization may be achieved in remote areas far removed from solidifying material mixing plants.

Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view of the swivel, drive connector and anchorage apparatus, in combination.

FIG. 2 is an oblique view of the swivel.

FIG. 3 is an oblique view of the swivel attached to a drive connector with a second end plate.

FIG. 4 is an oblique view of the drive connector with a second end collar.

FIG. 5 is an oblique view of one form of a composite pier used as a anchorage apparatus.

FIG. 6 is an oblique view of one form of a drilling tool used as a anchorage apparatus.

FIG. 7 is an oblique view of one form of a drilling tool used as a anchorage apparatus having a diagonal cut first end.

DETAILED DESCRIPTION OF THE INVENTION

While grout is the solidifying material of choice, the present invention is not limited to use with grout. Rather, it should be apparent that any solidifying material capable of being pumped under pressure may be used. As used herein, the term “anchorage apparatus” is meant to included all shafts, drills, bits, tools and the like capable of expressing solidifying material during the drilling process, be it during insertion of the anchorage apparatus, during removal of the apparatus, or both.

Referring to FIG. 1, in a preferred embodiment, the soil stabilization and anchorage system used in the method of the present invention 10 comprises three main components: a solidifying material swivel 2 for receiving both a power drive unit 68 and a solidifying material (not shown), a drive connector 4 operatively connected to the solidifying material swivel 2, and a anchorage apparatus 6 operatively connected to the drive connector 4.

Turning to FIGS. 2 and 3, solidifying material swivel, for example, grout swivel 2, has a first end 8 for operatively mating with power drive unit 68, for example, a rotary torque drive, a percussion drill, a jacking apparatus, a vibratory driving device, a hydraulic drill, and like drilling equipment. A second end 12 is fabricated to operatively mate with drive connector first end 14. In a preferred embodiment, swivel second end 12 attaches to swivel plate 18 for operative mating to drive connector first end plate 26. At least one hole 20 is fabricated into plates 18 and 26 for receiving fastener 22, for example, a bolt or pin.

Intake 16 is fabricated to receive a pressurized supply of solidifying material, for example, grout, concrete or polymer (not shown). Grout swivels are well known in the art, generally comprising a grout intake port feeding into a sealed casing which surrounds a drive shaft. A portion of the drive shaft within the casing is hollow with perforations to allow the grout to pass from the casing to the hollow portion of the drive shaft. The top of the drive shaft is blocked, while the bottom is open, thereby allowing the grout to exit through the rotating drive shaft while the casing remains stationary. The novel feature of swivel 2 used in the present invention is its adaptation for use in combination with the other components of the system described in detail below. In a preferred embodiment, swivel drive shaft 24 extends beyond swivel casing 38 to form swivel second end 12.

Drive connector 4 comprises first end 14 and second end 30 separated by shaft 32. In a preferred embodiment, drive connector first end 14 attaches to drive connector first end plate 26 for operative connection to grout swivel plate 18 and drive connector second end 30 attaches to drive connector second end plate 36 for operative connection to anchorage apparatus 6 having a connector plate for example, a composite pier upper pierhead plate (56, FIG. 5) (described below). At least one hole 20 is fabricated into plates 18, 26, 36 and 56 for receiving a fastener 22, for example, a bolt or pin. Drive connector shaft 32 is hollow for throughput transmission of solidifying material. Optional gasket 34 may be inserted between plates 18 and 26 and/or between 36 and 56 to control solidifying material seepage.

In another preferred embodiment shown in FIG. 4, drive connector second end 30 is adapted to operatively mate with anchorage apparatus 6 (FIG. 6) having a straight shaft end, for example, a conventional helical pier or straight shaft tool (both described below). Drive connector second end 30 operatively couples with the straight shaft end anchorage apparatus in a known manner such as that described in U.S. Pat. No. 6,615,554 to Rupiper, incorporated by reference. In all other aspects, drive connector 4 is as described above.

Alternatively, swivel second end 12 may be fabricated to terminate in the drive connector manners described above to directly operatively mate with anchorage apparatus 6, thereby eliminating the need for drive connector 4. Of course, the advantage of drive connector 4 is the cost savings associated with fabrication of multiple drive connectors 4 to fit differing anchorage apparatus 6, rather than multiple sizes of the more expensive to fabricate swivel 2.

FIG. 5 shows one form of a composite pier 40 used as the anchorage apparatus 6 in a preferred embodiment of the present invention. As used herein, the term “composite pier” is meant to include all anchorage apparatus having an assembly 42 used for mounting an above ground structure or component to the anchorage apparatus 6.

Assembly 42 is shown mounted to helical pier top portion 44 of known hollow helical pier shaft 46 having a sealed bottom end 48. Pier shaft 46 includes at least one helice 50 for advancing pier shaft 46 into a ground surface (not shown) and orifice 52 for expressing solidifying material. As I teach in my invention to which I now claim priority, in a preferred embodiment, orifice 52 is fabricated directly behind helice trailing edge 54 and at least one compaction fin 66 is attached to pier shaft 46. As used herein, the term “compaction fin” is meant to include any attachment mounted to pier shaft 46 which during the drilling process creates a space around the pier shaft 46 in which the solidifying material can flow (described further below).

However, one advantage of the improved installation method of the present invention is that by pre-drilling a pilot hole (described in detail below), the need to create a space around pier shaft 46 as it is being inserted is substantially eliminated. Therefore, as described in the present invention, when inserting a helice pier anchorage device, for example, a composite pier, into the pilot hole, there is no advantage to placing orifice 52 directly behind helice trailing edge 54. Orifice 52 may be located anywhere on pier shaft 46 without affecting final solidifying material consistency.

Dependant upon soil conditions, compaction fin(s) 66 may be omitted. In particular, if soil composition is such that soil surrounding the pilot hole does not collapse into the pilot hole, there is no need for compaction fin(s) 66. Of course, if soil composition is such that there is soil collapse into the pilot hole (such as would occur in, for example, loose, sandy soil), the addition of at least one compaction fin 66 is indicted for the reasons described above.

Composite pier assembly 42 includes upper pierhead plate 56, preferably a circular plate, mounted to pier shaft 46. Lower pierhead plate 58, preferably a circular plate, is also mounted to pier shaft 46. Pierhead plates 56 and 58 are spaced apart and are preferably fixedly attached, for example, welded, to pier shaft 46.

Pierhead plates 56 and 58 include bolt holes 60 disposed around their outer circumference. Bolt holes 60 are used to receive a portion of threaded rods 62. Plurality of nuts 64 are threaded on rods 62 for securing rods 62 to pierhead plates 56 and 58.

Bolt holes 20 of drive connector second end plate 36 (FIG. 3) are indexed above assembly bolt holes 60. An upper portion of the threaded rod 62 is received through drive connector bolt holes 20. Nuts 64 secure drive connector to assembly 42. Threaded rods 62 are shown disposed around the outer circumference of drive connector second end plate 36. Obviously, any number of threaded rods 62 and nuts 64 can be used with assembly 42 depending on the load conditions. Ideally, composite pier is inserted to a depth such that assembly upper pierhead plate 56 is located substantially at surface level, such that an above ground structure or component (not shown) may be mounted or anchored to threaded rods 62.

FIG. 6 shows one example of a conventional helical pier or drilling tool used as the anchorage apparatus 6 in another preferred embodiment of the present invention. As used herein, the term “conventional helical pier” is meant to include all anchorage apparatus having a straight shaft superior end substantially at or above surface level and the term “drilling tool” is meant to include all anchorage apparatus which are not left in the ground.

Drive connector second end 30 (FIG. 4) forms collar 70 which receives upper end 72 of anchorage apparatus shaft 74. Optionally, shaft upper end 72 includes a diagonal cut 76 (FIG. 7) received by optional mating diagonal stop 78 fabricated within collar 70 (FIG. 4). Diagonal cut 76 can be cut at an angle of about 5 to about 60 degrees perpendicular to a center line along a length of shaft 74. In this manner of coupling, the ability to apply increased torque along the length of shaft 74 is greatly improved when driving anchorage apparatus 6 into the ground surface.

Optionally, upper end 72 includes one or more holes 80, as does collar 70 (FIG. 4). Holes 80 are fabricated to align to receive fastener 22, for example, a bolt or pin, used to retain drive connector 4 to upper end 72, and to further prevent rotation of shaft 74 within collar 70. Optionally, shaft 74 and mating collar 70 have an octagonal or other geometric configurations to further aid in preventing rotation of shaft 74 within collar 70.

In use, the present inventions operates as follows: After determining the precise location and angulation required of installed pier shaft 46, a pilot hole is drilled using conventional drilling techniques to a predetermined depth and at the required angulation. An advantage of drilling a pilot hole is that obstacles or impediments to placement of anchorage apparatus 6 are discovered prior to anchorage apparatus 6 insertion. In a preferred embodiment, pilot hole depth is equal to substantially the length of pier shaft 46 to be contained within soil. The diameter of the pilot hole is greater than the diameter of pier shaft 46 and compaction fin 66 (if present) by an amount such that the resulting solidifying material column encasing pier shaft 46 effectively increases lateral stability of pier shaft 46. In a preferred embodiment, the pilot hole is at least about ¼ inch greater in diameter than the diameter of pier shaft 46 and compaction fin 66 (if present) and most preferably about 1 inch greater.

When the installed anchorage apparatus 6 is a composite pier, the pilot hole diameter is increased in that area of the soil which will receive assembly 42. In this area, the diameter of the pilot hole is greater than the diameter of assembly 42 such that the resulting solidifying material column encasing assembly 42 effectively increases lateral stability of assembly 42. In a preferred embodiment, the pilot hole is at least about ¼ inch greater in diameter than the diameter of assembly 42 and most preferably about 1 inch greater.

In a preferred embodiment, after selecting anchorage apparatus 6, swivel 2 is attached to a power drive unit. Drive connector 4 having first 14 and second 30 ends capable of operably mating to swivel 2 and anchorage apparatus 6 respectively, is selected and attached to swivel 2. Thereafter, anchorage apparatus is attached to drive connector 4 and a solidifying material supply hose is attached to swivel solidifying material intake.

Solidifying material is pumped under pressure during anchorage apparatus 6 insertion, preferably continuously throughout the entire insertion operation. Although the present invention may be used without limitation to pumping pressures (other than seal and connection tolerances), preferably, the solidifying material is delivered with a pumping pressure of less than about 500 lbs psi and more preferably with a pumping pressure of about 100 to 200 lbs psi and most preferably with a pumping pressure of about 150 lbs psi.

Delivering solidifying material throughout the insertion procedure as taught by the present invention prevents the solidifying material voids found with known technology. Furthermore, the present invention creates a column of solidifying material completely encasing the pier shaft, resulting in significant improvements to both pier shaft corrosion resistance and to soil stabilization and anchorage over previously known methods.

Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims. 

1. A method of placing a soil stabilization and anchorage apparatus comprising the steps of: a. pre-drilling a pilot hole into a ground substrate to a pre-selected depth and at a pre-selected angulation; b. operatively attaching a power drive unit to the anchorage apparatus; c. engaging the power drive unit to insert the anchorage apparatus into the pilot hole; d. pumping a pressurized supply of solidifying material through the anchorage apparatus such that the solidifying material is pumped during the inserting operation and expressed through at least one anchorage apparatus shaft orifice to create a substantially voidless column of solidifying material encasing an anchorage apparatus shaft; and d. removing the power drive unit from the anchorage apparatus.
 2. The method of claim 1 wherein the pilot hole depth is substantially equal to a length of shaft to be contained within the ground substrate, and the diameter of the pilot hole is larger than the diameter of the shaft by an effective dimension such that the substantially voidless solidifying material column encasing the shaft effectively increases lateral stability of the shaft.
 3. The method of claim 1 wherein the anchorage apparatus is a composite pier having at least one compaction fin attached to the shaft, the pilot hole depth is substantially equal to a length of shaft and composite pier assembly to be contained within the ground substrate, the diameter of the pilot hole is larger than the diameter of the shaft and compaction fin by an effective dimension such that the substantially voidless solidifying material column encasing the shaft effectively increases lateral stability of the shaft, and the pilot hole includes a counter sunk portion for receiving the assembly, the portion having a diameter larger than an assembly diameter by an effective dimension such that the substantially voidless solidifying material column encasing the assembly effectively increases lateral stability of the assembly.
 4. The method of claim 1 wherein the diameter of the pilot hole is at least ¼ inch larger than the diameter of the shaft.
 5. The method of claim 3 wherein the diameter of the pilot hole is at least ¼ inch larger than the diameter of the shaft and compaction fin and the diameter of the counter sunk portion is at least ¼ inch larger than the diameter of the assembly.
 6. The method of claim 3 further including the step of mounting an above ground structure to the inserted composite assembly.
 7. A method of placing a soil stabilization and anchorage apparatus comprising the steps of: a. pre-drilling a pilot hole into a ground substrate to a pre-selected depth and at a pre-selected angulation; b. operatively attaching a power drive unit to a solidifying material swivel; c. operatively attaching the solidifying material swivel to a hollow anchorage apparatus shaft, wherein; the solidifying material swivel includes a first end for operatively receiving the power drive unit, a second end for operatively receiving the anchorage apparatus, and a swivel casing therebetween having a solidifying material intake port for stationaryly receiving a supply of solidifying material, wherein a swivel drive shaft extends beyond the swivel casing to form the swivel second end and the hollow anchorage shaft includes at least one orifice for expressing a solidifying material; d. engaging the power drive unit to insert the anchorage apparatus into the pilot hole; e. pumping a pressurized supply of solidifying material through the intake port during the inserting such that the solidifying material is pumped during the inserting operation and expressed through the at least one orifice to create a substantially voidless column of solidifying material encasing the shaft; and f. removing the power drive unit and solidifying material swivel from the anchorage apparatus.
 8. The method of claim 7 wherein the pilot hole depth is substantially equal to a length of shaft to be contained within the ground substrate, and the diameter of the pilot hole is larger than the diameter of the shaft by an effective dimension such that the substantially voidless solidifying material column encasing the shaft effectively increases lateral stability of the shaft.
 9. The method of claim 7 wherein the anchorage apparatus is a composite pier having at least one compaction fin attached to the shaft, the pilot hole depth is substantially equal to a length of shaft and composite pier assembly to be contained within the ground substrate, the diameter of the pilot hole is larger than the diameter of the shaft and compaction fin by an effective dimension such that the substantially voidless solidifying material column encasing the shaft effectively increases lateral stability of the shaft, and the pilot hole includes a counter sunk portion for receiving the assembly, the portion having a diameter larger than an assembly diameter by an effective dimension such that the substantially voidless solidifying material column encasing the assembly effectively increases lateral stability of the assembly.
 10. The method of claim 7 wherein the diameter of the pilot hole is at least ¼ inch larger than the diameter of the shaft.
 11. The method of claim 9 wherein the diameter of the pilot hole is at least ¼ inch larger than the diameter of the shaft and compaction fin and the diameter of the counter sunk portion is at least ¼ inch larger than the diameter of the assembly.
 12. The method of claim 9 further including the step of mounting an above ground structure to the inserted composite assembly.
 13. The method of claim 7 wherein the solidifying material is a material selected from the group consisting of grout, concrete and polymer.
 14. A method of placing a soil stabilization and anchorage apparatus comprising the steps of: a. pre-drilling a pilot hole into a ground substrate to a pre-selected depth and at a pre-selected angulation; b. operatively attaching a power drive unit to a solidifying material swivel; c. operatively attaching the solidifying material swivel to a hollow drive connector; d. operatively attaching the hollow drive connector to a hollow anchorage apparatus shaft, wherein; the solidifying material swivel includes a first end for operatively receiving the power drive unit, a second end for operatively receiving the hollow drive connector, and a swivel casing therebetween having a solidifying material intake port for stationaryly receiving a supply of solidifying material, wherein a swivel drive shaft extends beyond the swivel casing to form the swivel second end; the hollow drive connector includes a first end operatively connected to the solidifying material swivel and a second end for operatively receiving the hollow anchorage apparatus shaft; and the hollow anchorage apparatus shaft includes at least one orifice for expressing a solidifying material during the placing; e. engaging the power drive unit to insert the anchorage apparatus into the pilot hole; f. pumping a pressurized supply of solidifying material through the intake port during the inserting such that the solidifying material is pumped during the inserting and expressed through the at least one orifice to create a substantially voidless column of solidifying material encasing the shaft; and f. removing the power drive unit, the solidifying material swivel, and the hollow drive connector from the anchorage apparatus.
 15. The method of claim 14 wherein the pilot hole depth is substantially equal to a length of shaft to be contained within the ground substrate, and the diameter of the pilot hole is larger than the diameter of the shaft by an effective dimension such that the substantially voidless solidifying material column encasing the shaft effectively increases lateral stability of the shaft.
 16. The method of claim 14 wherein the anchorage apparatus is a composite pier having at least one compaction fin attached to the shaft, the pilot hole depth is substantially equal to a length of shaft and composite pier assembly to be contained within the ground substrate, the diameter of the pilot hole is larger than the diameter of the shaft and compaction fin by an effective dimension such that the substantially voidless solidifying material column encasing the shaft effectively increases lateral stability of the shaft, and the pilot hole includes a counter sunk portion for receiving the assembly, the portion having a diameter larger than an assembly diameter by an effective dimension such that the substantially voidless solidifying material column encasing the assembly effectively increases lateral stability of the assembly.
 17. The method of claim 14 wherein the diameter of the pilot hole is at least ¼ inch larger than the diameter of the shaft.
 18. The method of claim 16 wherein the diameter of the pilot hole is at least ¼ inch larger than the diameter of the shaft and compaction fin and the diameter of the counter sunk portion is at least ¼ inch larger than the diameter of the assembly.
 19. The method of claim 16 further including the step of mounting an above ground structure to the inserted composite assembly.
 20. The method of claim 14 wherein the solidifying material is a material selected from the group consisting of grout, concrete and polymer.
 21. A soil stabilization and anchorage apparatus formed by the method of claim
 1. 